What is the video ad serving template (VAST)?
The definition of VAST tag
A VAST tag is a third-party ad tag generated by an ad server to deliver seamless video ads. With 85% of businesses using video as a marketing tool, it’s essential app marketers understand the basics of a VAST tag.
What is a VAST tag?
The Video Ad Serving Template (VAST) was developed by the Interactive Advertising Bureau as a framework to embed third-party video ads into a video stream. This framework provides a standardized structure enabling advertisers to serve ads across multiple ad inventories within various video ad players.
A VAST tag is an ad script generated by ad servers that allows ad servers to communicate with video players. More specifically, a VAST tag is a piece of code — an XML markup schema — placed on a publisher’s website to display ads.
The tag contains the requirements of the ad, such as the type of ad or dimensions of the ad, which guarantee that the video ad will play as expected. See further VAST tag examples below.
VAST tag examples
- The destination URL (for when the ad is clicked)
- The running time of the video ad
- The location of the video ad
Advertisers can create a VAST tag manually, with Google Ad Server, or using a third-party tool. While some elements of a tag will vary depending on the requirements of an advertiser or publisher, there are three main elements that exist in every tag.
- Media file: This contains the advertiser’s ad creative.
- Video format: This determines the format of the ad creative.
- Tracking pixels: These track user behavior and conversions.
How does a VAST tag operate?
A VAST tag functions in three separate processes for ad insertion as listed below:
- The video player sends a request to the ad server to retrieve the video ad.
- Once the ad server receives the request, it replies with an inline response containing the media file and requisite tracking URLs.
- The video is played, and then the video player uses the tracking URL to record impressions of the video.